JPH03222340A - Circuit board to mount semiconductor device on - Google Patents

Abstract

PURPOSE:To facilitate the manufacture of the title circuit board and to improve the accuracy of the alignment of the circuit board to the pad parts of a semiconductor device by a method wherein parts, which are formed on glass pastes, of a conductor circuit are formed at positions to correspond to the pad parts of the device, which is subjected to face down bonding on the board. CONSTITUTION:When the size of Al pads 16 of a semiconductor device 15 is assumbed to be x2 (breadth) X y2 (length) and the dimension (size) of a conductor circuit 12 on glass pastes 11 which are projected parts 14 is assumed to be x1 (breadth) X y1 (length), a circuit board is formed so as to satisfy the relations of x1<x2 and y1<y2. Here, the (x1) is equal to the width of the glass pastes 11 formed in the direction orthogonal to the circuit 12 and the (y1) is equal to the width of the circuit 12. The device 15 is subjected to face down bonding on the circuit board formed in such a way by thermal pressure bonding. In such a way, the projected parts 14 of the circuit 12 constitute electrode parts. Accordingly, the omission of a bump formation process is contrived and the mass production of the circuit board is facilitated.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a circuit board on which a semiconductor device is mounted.

[Conventional technology]

Conventionally, a semiconductor device and a protruding electrode hump formed on a substrate are bonded by face-down bonding, as shown in FIGS. 5 and 6. 1 to a pad (not shown) formed on the semiconductor device 1 and a protruding electrode bump 4 formed on the conductor circuit 3 on the substrate 2 (as shown in FIG. 5) by a thermocompression method that applies heat and load. The one shown is a gold (Au) hump, and the one shown in FIG. 6 is a solder hump).

[Problems to be Solved by the Invention] However, in such a conventional example, the protruding electrode hump 4
must be formed on the conductor circuit 3 on the substrate 2, but this manufacturing process is not easy and requires a large number of steps because it uses dry etching or wet etching. There are many problems such as alignment accuracy.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a circuit board for mounting a semiconductor device that is easy to manufacture and has an electrode portion that has good positioning accuracy with the pad portion of the semiconductor device. It's about doing.

[Means for Solving the Problems] In order to solve the above problems, the present invention screen-prints liquid glass on a substrate, cures the liquid glass, and then applies electroless plating to a conductor circuit made of a copper-based material. Accordingly, in the circuit board for mounting a semiconductor device formed over the hardened glass, the portion of the conductor circuit formed on the glass is attached to a pad portion of a semiconductor device that is face-down bonded onto the board. It is characterized by being formed at corresponding positions.

[Embodiment] FIGS. 1 to 3 show an embodiment of the present invention, in which FIG. 1 is a sectional view showing a state in which a semiconductor device is mounted on a circuit board, FIG. 2 is a top view of the circuit board, and FIG. FIG. 3 is a back view of the semiconductor device.

In the circuit board for mounting a semiconductor device according to this embodiment, a glass paste (liquid glass) 11 is screen printed on a substrate 10 made of ceramic, for example, and then hardened. Next, Cu is deposited by electroless plating.

A conductor circuit 12 made of a copper-based material such as Ni is formed. A gold thread material (or an indium alloy may be used) 13 is deposited on the conductor circuit 12 by electrolytic plating.

Here, conductor circuit 12 formed on glass paste 11
protrudes from the substrate lO plane by the thickness of the glass paste 11, and this protruding portion 14 is bonded to the aluminum pad 16 of the semiconductor device 15 as shown in FIG. The dimensions (size) of the circuit 12 have the following limitations. That is, as shown in FIG. 3, the size of the aluminum pad 16 of the semiconductor device 15 is
If xz (horizontal) and Xyz (vertical) are the dimensions (size) of the conductor circuit 12 on the glass paste 11, which is the protruding portion 14, are x+ (horizontal) and Xy+ (vertical), then x, < xz・
The relationship yI<yl must be satisfied. Here, the X1 is a glass paste 1 formed perpendicularly to the conductor circuit 12.
1, yl is equal to the width of the conductor circuit 12.

A semiconductor device 15 is placed on the circuit board thus formed.
Perform face-down bonding using thermocompression bonding.

At this time, the aluminum band 16 of the semiconductor device 15 and the gold thread material 13 on the upper layer of the conductor circuit 12 are bonded by forming an alloy layer by Au--Al diffusion.

In this manner, in this embodiment, the protruding portion 14 of the conductor circuit 12 constitutes the electrode portion, so that the conventional hump forming process can be omitted and mass production can be facilitated. Furthermore, since the protruding portions 14 of the conductor circuit 12 are formed by screen printing, the alignment accuracy with the aluminum pads 16 of the semiconductor device 15 is also improved. Furthermore, since the aluminum band 16 of the semiconductor device 15 and the conductor circuit 12 are directly bonded by thermocompression, the heat generated in the semiconductor device 15 is transmitted through the conductor circuit 12 and is quickly dissipated. Therefore, it has very good heat dissipation characteristics and is suitable for mounting a power device that generates a large amount of heat.

Further, since the semiconductor device 15 is directly connected to the conductive circuit 12, the signal transmission distance is extremely short, and the signal delay time can be shortened. Therefore, it is also suitable as a board for mounting devices that operate at high speed.

Note that the present invention is of course not limited to the above-mentioned embodiments. For example, the glass paste 11 formed on the substrate 10 may be applied to the aluminum of the semiconductor device 15 on which the protruding portion 14 of the conductor circuit 12 is mounted. As long as it faces the pad 16 and is smaller in size than the aluminum pad 16, it may be printed in any way.

For example, in the example shown in FIG. 2, the glass paste 11 is formed to be perpendicular to the conductor circuit 12, and in the example shown in FIG. 4, the glass paste 11 is formed in a rectangular shape at the center of 110. Alternatively, it may be formed by printing grooves and grooves at positions facing the aluminum pad 16, respectively.

In the above embodiment, the conductive circuit 12 is connected to the aluminum pad 16 and the A
u-Aj! Although they are bonded by diffusion, the conductor circuit 12
Without plating the gold thread material 13 on the upper layer of Cu-Aj!
Bonding can also be performed by diffusion.

However, if only the lower layer copper-based material is used, the bonding reliability will not be good.

[Effects of the Invention 1] As described above, the present invention screen-prints liquid glass on a substrate, hardens the liquid glass, and then spreads a conductor circuit made of a copper-based material over the hardened glass by electroless plating. In this circuit board for mounting a semiconductor device, the portion of the conductor circuit formed on the glass is formed at a position corresponding to a band portion of a semiconductor device that is face-down bonded onto the substrate. With this feature, it is possible to provide a circuit board for mounting a semiconductor device that is easy to manufacture and has an electrode portion with good alignment accuracy with the pad portion of the semiconductor device.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention, FIG. 1 is a cross-sectional view showing a state in which a semiconductor device is mounted on a circuit board, FIG. 2 is a top view of the circuit board, and FIG. 3 is a semiconductor device mounted on a circuit board. FIG. 4 is a top view showing different embodiments of the present invention, and FIGS. 5 and 6 are sectional views showing conventional examples. DESCRIPTION OF SYMBOLS 10... Substrate, 11... Liquid glass, 12... Conductor circuit, 5... Semiconductor device, ■ 6... Pad.

Claims (1)

[Claims] (1) A circuit board for mounting a semiconductor device, which is obtained by screen printing liquid glass on a substrate, curing the liquid glass, and then forming a conductive circuit made of a copper-based material over the hardened glass by electroless plating. A circuit for mounting a semiconductor device, wherein the portion of the conductive circuit formed on the glass is formed at a position corresponding to a pad portion of a semiconductor device that is face-down bonded onto the substrate. substrate.